Generic 110v 2 Plug-in Cordless Wireless Digital Doorbell (White+blue) By Sistel Retail Packing Wireless Easy Mounting Design Never Affects Your Inner Decoration,Easy to Install with Double-side Sticker at the Back of the Remote Control and Makes the Doorbell Anywhere You Like 38 Polyphony Sounds Selections Up-dated Intelligent Flash Light Design Brings Convenience to the Hearing Handicapped All-day Anti-interference System - Prevents the Doorbell from Interferences Outside or Between Neighbors The Standard Wireless doorbell System Works Well When the Bedridden Need Help or Water, Coffee,etc. from Their Lover or Health Worker